In the formation of copper interconnects by Chemical Mechanical Polishing (CMP), benzotriazole (BTA) is used as a copper corrosion inhibitor in barrier CMP slurries and post-CMP cleaning formulations. Removal of BTA adsorbed on copper is important for the overall success of copper CMP process. In this study, adsorption/uptake of BTA and its removal from copper surface was investigated using a quartz crystal microbalance with dissipation monitoring capability (QCMD). Adsorption of BTA was carried out from a series of BTA solutions (20, 50, 100, 200 ppm) in tetramethylammonium hydroxide (TMAH) in the presence of hydrogen peroxide. Following the uptake step, removal of BTA by TMAH and acetohydroxamic acid (AHA) solutions maintained at pH 10 were studied in-situ. TMAH solutions remove some physisorbed BTA, while AHA is able to completely remove BTA.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials